Exterior mounting block for electrical fixtures

ABSTRACT

An exterior mounting block for electrical fixtures includes a plastic block having a nailing flange and screw holes adapted to support either a duplex outlet or a light fixture. The holes are spaced either along the central axis of the block for a duplex, or spaced diagonally relative to each other on sidewalls to support a light fixture. The block is formed from a white, fire-resistant material and includes a cover plate formed from a non-fire-resistant material or from a metal material.

RELATED APPLICATION

This application is a continuation-in-part application of U.S.application Ser. No. 10/253,351, filed Sep. 24, 2002 now U.S. Pat. No.6,723,921, entitled EXTERIOR MOUNTING BLOCK FOR ELECTRICAL FIXTURES, thedisclosure of which is incorporated in its entirety herein by reference.

BACKGROUND

The use of lapped siding, i.e., vinyl, aluminum, etc., on buildingsincreases the difficulty of mounting electrical fixtures such as lightfixtures, electrical outlets and the like to the sides of buildings. Aproduct was developed which provided a mounting surface for theelectrical fixture and was easily integrated into siding. This device isdisclosed in Vagedes et al., U.S. Pat. No. 4,726,152. This is mounted tothe side of a building with or without the use of an electrical box. Theproblem with this mounting block and similar blocks is that it is notfire resistant. To be fire resistant, a mounting block must be made froma fire resistant plastic and further there must be an electric boxattached to the rear surface of a mounting block. Generally mountingblocks are not deep enough for a standard electric box.

Making the mounting block itself fire resistant significantly increasesthe cost of the product. One attempted solution to this problem isdisclosed in U.S. Pat. No. 6,359,220 which uses a mounting block thathas an electrical box that snap fits into the opening. The electricalbox made from fire resistant material is attached directly to theelectrical fixture. In order to facilitate electrical wires andelectrical outlets, the box needs to be significantly deeper making themounting block somewhat unsightly.

Plastic mounting blocks generally match the color of the siding. Sidingcomes in a wide variety of colors. Thus, stocking mounting blocks whichmatch all siding colors is very expensive. Further, fire resistantmaterial is not available in all colors.

Another issue is mounting of electrical fixtures either lights oroutlets. Both of these are attached with two screws. But, the screw holespacing for outlets is not the same as the spacing for light fixtures.

SUMMARY OF THE INVENTION

The present invention is premised on the realization that a fireresistant mounting structure for an exterior electrical fixture can beformed from a mounting block having a flange, a front wall and four sidewalls. A standard opening is provided in the front wall. The interior ofthe mounting block holds a separate fire resistant electric box that hasan opening substantially larger than the opening on the front surface ofthe mounting block. Interposed between the electric box and the mountingblock is a separate fire resistant plate which restricts the opening onthe electric box making it correspond in size to the opening in themounting block. The interposed plate and the electric box are formedfrom fire resistant material. This combined structure is fire resistant.At the same time this provides more than adequate room for electricalwiring and/or an electrical outlet. The electric box can include foursupports that extend from each corner. These supports locate the box andplate in the mounting block.

Preferably the structure includes a peripheral ring that snaps on toconceal the cut edges of siding.

Further, in a preferred embodiment, the structure includes a plate whichmounts onto the front surface and covers the front surface as well asthe peripheral ring. If the plate is metal, it makes the mounting appearto be metal such as brass or the like. Plastic plates can be used tomatch the color of the siding. Thus, only one color mounting block isrequired and less expensive cover plates can be used to match the sidingcolor. Alternatively, the entire block can be formed from fire resistantmaterial, generally in white. This eliminates the need for a plate onthe electrical box. The color can be changed by use of a colored covereither with or without a ring. The cover does not need to be fireresistant.

Preferably, the electrical box includes two sets of holes. The first setis adapted to accept an outlet. The second set, fixed diagonally,accepts a light fixture.

The objects and advantages of the present invention will be furtherappreciated in light of the following detailed description and drawingsin which:

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a perspective view of the structure of the present inventionpartially broken away.

FIG. 2 is an exploded view of the FIG. 1.

FIG. 3 is a perspective view of the electrical box and interposed plate.

FIG. 4 is a perspective view of the mounting box covering the interposedplate and the electrical box.

FIG. 5 is a perspective view partially broken away depicting a coverplate covering the structure of the present invention.

FIG. 6 is a plan view of the electric box used in the present invention.

FIG. 7 is a cross-sectional view of the cover plate taken at lines 7—7of FIG. 5.

DETAILED DESCRIPTION

As shown in FIGS. 1 and 2, the present invention is a mounting structure10 for an electrical light fixture, electric outlet or the like (notshown). The mounting structure includes an innermost electric box 12which is covered by a mounting block 14. A cover plate 16 is interposedbetween the electric box 12 and a front wall 18 of the mounting block14. This combined structure is attached to a wall 22 of a building asshown in FIG. 1 with siding 24 abutting the side walls 26, 27, 28 and 29of mounting block 14.

The edges of the siding are then in turn covered with an exteriorsnap-on ring 34. The entire structure 10 can in turn be covered by aplate 36 as shown in FIG. 5.

More particularly, the electric box includes four side walls 38, 39, 40and 41, locating supports 44 extended tangentially from each corner 42.Inwardly extended portions 46, 47, 48, 49 from the side walls supportscrew holes 55, 56, 57, 58. These four screw holes in the electrical box12 are positioned so that they can facilitate mounting of either anelectrical light fixture with holes 55 and 57 diagonally spaced at3.5″±0.25″ (center to center) or an electrical duplex outlet withvertically spaced holes 56 and 58 spaced at 3.25″±0.25″ (center tocenter). Holes 56 and 58 are located on first opposite sides 39 and 41and holes 55 and 57 are located on second opposites 38 and 40. Holes 56and 58 are located along what is the central axis of block 14.Preferably, the diameter of holes 55 and 57 is slightly larger than thediameter of holes 56 and 58. A light fixture is usually mounted withnumber 8 screws. A duplex outlet is attached with number 6 screws.

Back wall 62 of the box includes a punch out 64 for a mechanical wirefastener or alternately a fastening tab 66 to receive electric cablesuch as Romex brand cable. Each of the inwardly extended portions 46-49includes a boss 68(a), (b), (c), (d) which extend slightly above theforward edge 72 of the electric box 12. This extends roughly thethickness of plate 16 and therefore is flush with the forward surface 74of plate 16 when assembled with plate 16 resting on edge 72 of box 12.Electric box 12 also includes a boss 50 designed to receive a groundscrew.

Plate 16 is sized to cover electric box 12. Plate 16 further includes astandard sized, non-square, rectangular opening 76 generally 2″ by 3½″and also includes four cut out portions 77 a, b, c, d adapted to receivethe bosses 68 of the extended portions 46-49. Plate 16 is simplypositioned over the electric box 12 completely covering the opening ofthe box 12. This forms a complete fire resistant electric box. Cut outportions 77 a and 77 c are larger than bosses 68 a and 68 d providing anopen area aligned with open areas in box 12. This provides clearance formounting screws for light fixtures and GFI coverplates. The front wallof block 14 has corresponding openings.

The mounting block 14 in turn has a peripheral flange 78, extended fromside walls 26-29. Front wall 18 includes an opening 79 corresponding insize and shape to the opening 76 in plate 16. This opening should beabout equal to or larger than the opening in plate 16. The four supports44 of the electric box 12 engage the internal surface of the fourcorners 80 of block 14 aligning all these elements and provide a wedgefit.

Ring 34 which snap fits over block 14 has an internal surface 82corresponding to the four walls 27-30 of the mounting block 14. Itincludes first and second tabs 84 (only left side showing) which areadapted to snap into first and second indentations 88, 90 in the sidewalls 27 and 29 of the mounting block 14. This ring 34 simply covers theexterior edges of siding once the unit 10 is installed.

To install the unit of the present invention, a wire 92 is attached tothe electric box 12 either through the opening at tab 66 or with anelectrical connector through knockout 64. The plate 16 is then placedover the electric box 12 and the mounting block 14 is placed over thecombined electric box 12 and plate 16. The supports 44 will properlylocate the box 12 within the mounting block 14 to center the screw holes58 in the box 12 with the openings 77 in plate 16 in the front wall 18of the mounting block 14. The wall flange of block 14 is nailed to theexterior wall 22 of a building. This holds the electric box 12 and plate16 compressed between the wall 22 and front wall 18 of block 14. Siding24 is attached to the building abutting the four walls of the mountingblock 14. Ring 34 is snap fitted onto the side walls 27 and 30 of themounting block 14. The top of ring 34 is flush with the front wall 18 ofthe mounting block 14.

An electrical fixture (not shown) can then be attached to the wire 92 inthe electric box 12 and screwed onto box 12 using holes 56 and 58 or 55and 57. Depending on the type of fixture, the open area above and belowmounting holes 56 and 58 will provide clearance for fixture mountingscrews. This combination of two sets of holes and the open areas aboveand below holes 56 and 58 permits most light fixtures, switches andoutlets to be mounted.

A cover plate 36 can be employed to cover the entire mounting structure10 positioned between structure 10 and the electric fixture and providea unique appearance. As shown in FIG. 5, plate 36 covers the entirefront surface of wall 18 and extends beyond the edge of the mountingblock 12 and the ring 34. As shown in FIG. 7, plate 36 includes crossshaped bosses 95 or tabs if the plate is metal. These bosses fit intoholes 96 in the surface 18 of block 14 and provide an interference fitto temporarily hold the plate 36 in place and act as a centeringmechanism to center the opening in the plate with the opening in thebox. An electrical fixture is attached to the box by screws or boltsextending from the electrical fixture into the screw holes 56 and 58 or55 and 57 and hold the plate in position. The plate can also be centeredby its lower surface corresponding in size and shape to the ring 34.These can provide an interference fit to temporarily hold the plate 36in place until the outlet or fixture is attached. The length of bosses95, are about the same as the thickness of wall 18.

This cover plate 36 can be used with or without the ring 34 and can beused with any plastic mounting block as long as the plate has adimension which extends beyond the side walls of the mounting block 12.Thus, it can be used to retrofit existing mounting blocks. Plate 36 canbe plastic, metal, or metal coated plastic. Further, it can be squarerectangular or oval, i.e., nonrectangular. It can be significantlylarger than the block and used to mount a coach fixture, i.e., where thefixture is larger than the block.

As indicated, the electric box 12 and plate 16 are preferably made froma fire resistant plastic or metal suitable for an exterior building.Their color is not relevant as they will be totally concealed by themounting block 14 and any electrical fixture. The block 14 and ring 34can then be formed from a different non-fire rated plastic. This reducesthe cost of structure 10 while maintaining overall fire resistance. Thecolor of the block 14 and ring 34 should match or accent the siding 24.

The present invention provides a mounting structure for an electricalfixture which is fire resistant whereas the mounting block 14 itselfdoes not need to be made from fire resistant material. The innerelectrical box 12 and intermediate plate 16 provides the fire resistantstructure. Changing the color of the block will not affect the firerating of the product. This encases the electrical wiring within a fireresistant structure making it compliant with current electrical codes.Further, due to the use of the intermediate plate, an electrical box canbe molded or stamped to provide a large space for wiring without theneed for an unsightly deep mounting block. The permanent locatingsupports on the mounting box ensure that when it is assembled, theopening in the electrical box is properly located within the mountingblock and further facilitates quick assembly of the structure. Finally,the metal plate that can be attached to the exterior surface providing atruly unique appearance for the mounting block.

If the block 14 is made from a fire resistant material, plate 16 is notrequired. Further, the color can be changed by using plastic cover plate36 which has the desired color and which does not need to be fireresistant.

This has been a description of the present invention along with thepreferred method of practicing the invention, however, the inventionitself should only be defined by the appended claims wherein

I claim:
 1. A structure for mounting an electrical fixture comprising aplastic mounting block having a peripheral nailing flange, four sidewalls extending from said peripheral flange and a front wall having aperipheral edge and a first opening adapted to provide a wire connectionbetween an electrical fixture and wiring within a building; a platecovering said front wall of said mounting block said plate extendingbeyond the peripheral edge of said front wall and having a secondopening aligned with said first opening in said front wall.
 2. Thestructure claimed in claim 1 wherein said plate and said block areformed from different materials.
 3. The structure claimed in claim 2wherein said block is formed from a white plastic and said plate isformed from a non white plastic.
 4. The structure claimed in claim 3wherein said block is formed from a fire resistant material.
 5. Thestructure claims in claim 2 wherein said plate is metal.
 6. Thestructure claimed in claim 1 wherein said plate is nonrectangular. 7.The structure claimed in claim 1 further comprising a mechanism tocenter said second opening with said first opening.
 8. A mounting blockfor the exterior of a building having mounting surfaces; an openingthrough said mounting surfaces having a first and second set of oppositesides, and a front wall; a first pair of cut out portions on said frontwall and having a distance between each other and said first pair ofcutout portions aligned along a central axis of said block; a secondpair of cutout portions on said front wall, said second pair of cut outportions having a second distance between each other and positioneddiagonally from each other; wherein said first distance is differentthan said second distance and said pairs of cut out portions aredesigned to permit mounting of different electrical structures.
 9. Themounting block claimed in claim 8 wherein said opening is a non squarerectangle.
 10. The mounting block claimed in claim 8 wherein said firstset of holes are 3.25″±0.25 inch apart and said second set of holes are3.5″±0.25″ apart.
 11. The mounting block claimed in claim 8 wherein saidsecond set of holes each has a larger diameter than a diameter of eachof said first set of holes.